“And he worshiped.” This refers to Samuel and is a summary statement showing that Hannah’s prayer and promise had come to pass.
“lend...lent.” The Hebrew has a word-play on “ask.” “Ask” is shaal, and “lent” is from the same Hebrew root. But “lend” or more accurately “lend on request,” contains the idea that what is “lent” was asked for, and that is why there is the lexical tie between “ask” and “lend,” and the Hebrew text picks up on the lexical tie between the two words. We do not normally think of “lending” a child to Yahweh, especially since Samuel was “lent” for his whole life (“as long as he lives”) so Hannah would never expect to get him back, but the idea was not to be accurate in that way but rather to emphasize the fact that via Hannah’s vow, Yahweh in a sense asked for Samuel. This may also help Elkanah’s statement to Hannah, “May Yahweh fulfill His word.” Also, if Hannah felt that Yahweh in some manner asked for the child, along with her vow, that may have helped her let go of Samuel at such a young age.