וְהָיָ֥ה טֶֽרֶם־יִקְרָ֖אוּ וַאֲנִ֣י אֶעֱנֶ֑ה ע֛וֹד הֵ֥ם מְדַבְּרִ֖ים וַאֲנִ֥י אֶשְׁמָֽע׃
און עס װעט זײַן, אײדער זײ רופֿן, װעל איך ענטפֿערן, װי זײ רעדן נאָך, אַזו װעל איך צוהערן.
Kli Yakar
And I will bless those who bless you, and the one who curses you I will curse. The reason it doesn’t say “and I will curse those who curse you” in the same way it says and I will bless those who bless you, is because to man belong the arrangements of the heart (Proverbs 16:1). Before a person expresses any speech outwardly, he first arranges it in his heart and thoughts. It is known that regarding good deeds, the Holy One combines thought with action, but regarding evil thoughts, the Holy One does not combine them with action, as it is said: Had I seen iniquity in my heart, the Lord would not have heard (Psalms 66:18), and it is written: Before they call, I will answer (Isaiah 65:24). Because before a person expresses his request verbally, he has already contemplated it in his heart, therefore the Holy One answers from His holy heavens before he calls. This is different from flesh and blood, where when someone asks something from his fellow, he needs to express it with his lips because no person knows what is in another’s heart. But the Holy One, who examines hearts, fulfills all the desires of one’s heart, as it is written: May He grant you according to your heart (Psalms 20:5), and as it is said: To man belong the arrangements of the heart, but from the Lord comes the answer of the tongue (Proverbs 16:1). He wished to resolve this difficulty with this explanation: If truly the Holy One fulfills one’s request after it has been arranged in a person’s heart, then why did God command prayer with the mouth? To this he says, “from the Lord comes the answer of the tongue” — this is God’s gift that He gave the answer of the tongue to man. As our Sages said (Yevamot 64a), “The Holy One desires the prayers of the righteous.” This is because they are compared to the Holy One as a beloved child to his father — if the child asks something from his father, even though the father knows what the child needs, nevertheless, the father wants the child to express his request verbally because the father delights in the speech of the child’s lips. Similarly, the Holy One says to Israel, “Let me hear your voice, for your voice is sweet to approach Me.” The Holy One does not wish to conduct Himself with us like earthly rulers, who don’t allow much speaking before them and immediately when they understand the requester’s intention, they say “shorten your words” or “finish your speech and leave.” But the Holy One, in His kindness, is not so, as it is written: You have given him his heart’s desire, and the request of his lips You have not withheld, Selah (Psalms 21:3). Because we are in His eyes like a delightful child and precious son. This is what it means: Even though before they call, I will answer, nevertheless, while they are still speaking, I will hear, for I have not withheld from them the expression of their lips.
Or HaChaim
Another meaning of the additional words מפני נגשיו is in line with Isaiah 65,24 והיה טרם יקראו ואני אענה, "before they pray I will answer." In our situation G'd explains that He is sensitive to the abuse practised by even a single one of Israel's taskmasters. He does not wait until they all exceed their authority and abuse His people. G'd adds that the reason for this is that "I know their pains." The implication is that G'd is aware even before the people bring this to His attention through their prayer/outcry. All of this underscores G'd's strong love for His people, a love comparable to that of a father for his son.
Sforno
טרם כלה, he had not yet finished. This is what Isaiah 65,24 had in mind when he said that G’d answers a prayer before it has been articulated.