John Gill Commentary 1 Kings 19:5

"And he lay down and slept under a juniper-tree; and, behold, an angel touched him, and said unto him, Arise and eat." — 1 Kings 19:5 (ASV)

And as he lay and slept under a juniper tree
Being weary and fatigued with his journey, the same under which he sat; for there was but one, as that is said to be in the preceding verse:

behold, then an angel touched him, and said unto him, arise, and eat ;
so far was the Lord from granting his request to take away his life, that he made provision to preserve it; so careful was he of him, as to give an angel charge to get food ready for him, and then awake him to eat of it.