Our Able God

God backs his love and care for us (and we see that in his blank check to ask him what soever we desire) with his power, to deliver to us whatever it is that we desire. He meets our needs by his power, underscoring our desires by his abundant supply as a capable father.
God does not make empty promise. He has power to do what he says.

God asked howbeit rhetorically an 89 years old Sarah who naturally was past her prime and no longer able to have children "is any thing too hard for the Lord?"

Genesis 18:14
Is any thing too hard for the LORD ? At the time appointed I will return unto thee, according to the time of life , and Sarah shall have a son.

Jeremiah started his prayer by acknowledging that nothing is too hard before the Lord. And the Lord responded by acknowledging Jeremiah's resolve.

Jeremiah 32:17
Ah Lord GOD! behold, thou hast made the heaven and the earth by thy great power and stretched out arm, and there is nothing too hard for thee:

Jeremiah 32:27
Behold, I am the LORD, the God of all flesh: is there any thing too hard for me?

Nothing is certainly hard before our God. There are not off limit before the God of heaven and earth, that there is something He cannot do.

Gabriel, the angel, told Mary, to put a baby in the womb of a virgin without a man's help is a walk in the park for God.

Luke 1:37
For with God nothing shall be impossible.

Matthew 19:26
But Jesus beheld them, and said unto them, with men this is impossible; but with God all things are possible.

Of all the passages that details the ability of God to do all things, this is the strongest. Jesus here pointing to the Father's ability to complete the work of redemption without him dying. Of course, He completely surrendered to the Father's will (John 4:34, "...my meat is to do the will of him that sent me, and to finish his work."). Others are John 5:30, 6:38-39, 12:27, 18:11. Yet, here, he highlighted the ability of the Father above and beyond every obstacle.

Mark 14:35-36
And he went forward a little, and fell on the ground, and prayed that, if it were possible, the hour might pass from him. And he said, Abba, Father, all things are possible unto thee; take away this cup from me: nevertheless not what I will, but what thou wilt.

God's power is above and beyond in working to our advantage.

2 Corinthians 9:8
And God is able to make all grace abound toward you; that ye, always having all sufficiency in all things, may abound to every good work:

Philippians 4:19
But my God shall supply all your need according to his riches in glory by Christ Jesus.

So, to ask us to request of him is him making his power available to us to supply all that we need.

Why would he delay or stall when the power is with him? Proverbs 3:27-28