“In the Book of Exodus, we are told that if you come across a lost animal, even one belonging to an enemy, you must return it so that it comes to no harm. Similarly, if you see an animal struggling under a weight too heavy for it to bear, you are obligated to unburden the animal of the extra weight (Exodus 23:4-5). The ancient rabbis added to this injunction saying that after you have unburdened the animal you must accompany it for an unspecified distance to make sure that it is capable of carrying the load with which you have left it. This is the law even if the animal’s owner is standing nearby and observing what you are doing.
“Seeing to the welfare of one’s flocks and herds is mandated in Proverbs 27:23: ‘Stay apprised of the condition of your sheep; pay attention to the welfare of your cattle.’ This teaching may then provide the background to Jesus’ teaching regarding the lost sheep:
‘Who among you, owning a hundred sheep,
does not leave the ninety-nine
to go off in search of even one who is lost?’…
(Luke 15:4-7)
“While Jesus is clearly using the concern with one’s flocks metaphorically, the metaphor only works if the people listening to him share the value system that obligates them to care for their flocks and recover those who are lost.”