"If we look inward, and can say by experience that God has prepared our heart; we my look forward, and say with confidence that He will cause His ear to hear." Matthew Henry
This is such a blessed, comforting thought for if God so prepares and burdens my heart to pray for a certain thing so that indeed I do pour myself out to Him, will He shut His ear to my cry? It is the Spirit that gives such burdens that find no relief except at the Throne of Grace. So then we know when we leave the throne room what Hannah knew, "...her face no longer downcast" (1 Sam. 1:18). With our hearts now rejoicing at having been in God's presence, as was Hannah's experience, we know that we have prayed as 1 John 5:14-15 prescribes. "This is the confidence which we have before Him, that if we ask anything according to His will, He hears us. And we know that if He hears us in whatever we ask, we know that we have the requests which we have asked from Him." We know we have prayed fervently and effectively as in the promise of James 5:16, "...The effective, fervent prayer of a righteous man avails much."
"...wherever God finds a praying heart, He will be found a prayer-hearing God; though the voice of prayer be a low voice, a weak voice, yet if it comes from an upright heart, it is a voice that God will hear, that He will hear with pleasure, it is His delight, and that He will return a gracious answer to; He hath heard thy prayers, He hath seen thy tears." Matthew Henry