Charles Simeon comments on Isaiah 55:11:
It is not in the power of man to command a blessing on the word. “Paul may preach in vain, and Apollos water in vain, unless God give the increase.”
But if we pray to God, he will send us such a word as shall be suited to us; such a word as shall make us ready to think that the minister has received private information respecting us; such a word as shall discover to us our whole hearts, and constrain us to fall down on our faces, and confess that God is indeed present in his ordinances.
The minister may draw the bow at a ventures but God will direct the arrow between the joints of the harness, and cause it to pierce our inmost souls.
Let us then pray that God would direct and assist the minister, and render his word effectual to our good. Thus shall we secure to ourselves a blessing, and, like the refreshed earth, bring forth fruit suited to the culture bestowed upon us. (Horae Homileticae)