'Here Am I' in the Bible

But when he came to his senses he said, 'How many hired men of my father have more than enough to eat, and here am I perishing of hunger!

here am I, come in the name of my Father, and you will not accept me: let someone else come in his own name, and you will accept him!

Here am I all ready to pay you my third visit. And I will not be a burden to you; I want yourselves and not your money. Children have not to put money by for their parents; that is what parents do for their children.

and again, 'I will put my trust in him,' and again, 'Here am I and the children God has given me.'