Psalm 23:2a

He makes me lie down in green pastures.
This seems reminiscent of naptime battles when I tried to make one of my children take a nap against their will. I wanted to make them lie down!  But I don't think this is what the Psalmist means.  Here's what I learned about sheep that helps explain this sentence.
 Sheep are pretty skittish and nervous and unable to assuage their own fears.  In order for them to lie down and rest, circumstances need to be "just so".  Apparently, their requirements for rest are in four general areas:

1.  They must be assured of their own safety.  Their security cannot be threatened by predators or menacing weather conditions. Sheep are timid and fearful.  They need frequent reassurance to feel safe.
2.  Likewise, the sheep must not be agitated by unruly flock members. Animals respond to social order within their group, the sense of dominance or status.  When a bossy old sheep provokes other flock members, there is tension. Not rest.
3.  Sheep must not be pestered by pests.Particularly in the summer, sheep can be driven to extreme frustration by flies and parasites. When they are so tormented, they cannot think of lying down to rest; instead they are stamping their feet, shaking their heads, trying to rid themselves of these pests.
4.  Finally, they must be free from hunger. They are unable to find good grass and water on their own. If hungry, they are unable to rest; instead they wander off in hopes of something to fill their bellies.

In order for sheep to be able to lie down and rest, they must feel a sense of peace and security, freedom from fear, tension, aggravation, and hunger. The shepherd assumes the responsibility of ensuring that these conditions are met so that sheep feels secure enough to lie down and rest. He must be sure his sheep not only are safe but also feel safe. The quiet, calm, gentle presence of the shepherd is the best means to freedom from fear. Often times, a shepherd sleeps with his flock and lays himself at the door of their enclosure, protecting them from intruders.  If a bossy sheep-leader is grating on the nerves of the flock, the shepherd must either quiet him or remove him. Additionally, the shepherd must protect his charges from pests. He does this by clearing the grazing area and/or by applying insecticide meticulously to his flock.  (Interesting note: in Biblical times, oil was the primary protection against flies, ticks, and other pests.  Later in this Psalm, the Psalmist extols the Shepherd for "anointing his head with oil" - remember that for later.) Finally, the shepherd takes great pains to find and prepare good grazing land for his sheep.  This does not happen by chance - it requires a great deal of work on the part of the shepherd.

You are probably already drawing all the parallels.  Let's list them together.

1.  One of the (and possibly THE) most repeated phrase in all of Scripture is "Do not fear".  Over and over and over, God reassures us, comforts us, proves His protection for us. John 14:1 "Let not your heart be troubled" and John 16:33 - "In this world, you will have tribulation.  But, take heart; I have overcome the world." Jesus also tells us that He is the door.  Nothing can get through to us without His permission.  Also, He is the "door" to the Father.
2.  Jesus knows we need freedom not only from fear but also from tension in our relationships with other people.  Therefore, He directs us to be at peace with one another.  Consider Matthew 5:23,24 - "So if you are offering your gift at the altar and there remember that your brother ha something against you, leave your gift there before the altar and go.  First be reconciled to your brother and then come and offer your gift."  Time and time again, Scripture tells us that our relationship to God is compromised when we are striving with our brothers and sisters.  Simply put, we are unable to rest in Him very well if there is something wrong between us and someone else.  And if we have been bruised by the horns of an uncaring fellow-sheep or injured in a head-butting incident, the Good Shepherd wants to take us in His arms and tend our wounds.  He will bind up the broken-hearted; He will hold us and not let us go.  He invites us to cast our care on Him, because He cares about how we hurt.
3.  Being bothered by pests parallels the attacks believers experience by Satan and his minions.  The Good News is that The Good Shepherd has already triumphed over them. He has provided us armor to withstand the attacks (Ephesians 6:10-18).  We just have to submit to Him and resist the enemy - the enemy will flee (James 4:7).
4.  Jesus meets our physical needs (Matthew 6:25-34).  He points out to us that, if God feeds the bird and clothes the flowers, then surely He will provide what we need.  We don't have to worry.  Even better than meeting our physical needs, though, He satisfies the deepest hunger of our souls.  With Himself.  "I am the bread of life; whoever comes to me shall not hunger and whoever believes in me shall never thirst"(John 6:35,36)

Scripture often exhorts us to "rest in Him".  And we can indeed rest.  Because all the conditions necessary for us to lie down in green pastures are met. 

One last thought to treasure about Jesus having us lie down in green pastures.The Hebrew word that is translated "pastures" is "Na'ah".  It conveys the idea of home, habitation, a dwelling, a pleasant place.  Isn't that a wonderful thought?  Home.  The word carries the feeling of belonging, acceptance, security, unconditional love.  The place of rest in Christ isn't just any green pasture.  It's where we belong.  It's home.

And, one day, we'll go to the pasture that He has been preparing for us for 2000+ years.  Our Father's house.  Home.