"And when My servants ask you..."
The shift in the mode of address, while directing it toward the Master of the possessors of intellect—upon him be prayer and peace—contains an obvious honor and elevation of status.
"About Me"—that is, about My nearness and distance, for the question is not about His Essence, the Exalted.
"Indeed, I am near"—that is, say to them: that you may inform them of this nearness by any means. A prepositional phrase must be implied [i.e., "Say: I am near"], for without it, the apodosis does not follow the conditional clause. It is not explicitly stated, as is the case in similar instances, to indicate that He, the Exalted, has taken charge of answering them Himself and has not entrusted them to His Messenger—may the blessings and peace of Allah be upon him—as a sign of the perfection of His kindness.
"Nearness" is, in reality, spatial proximity, which is far removed from Him, the Exalted. Thus, it is a metaphor for His knowledge of the actions and words of His servants and His awareness of all their conditions. Sufyan ibn 'Uyaynah and Abdullah ibn Ahmad narrated from Ubayy [ibn Ka'b] that he said: The Muslims said, "O Messenger of Allah, is our Lord near so that we may converse with Him in whispers, or far so that we may call out to Him?" So Allah revealed this verse.
"I respond to the call of the supplicant when he calls upon Me" is evidence for this nearness and a confirmation of it; thus, the separation [between the clause and the answer] is for the perfection of connection. It contains a promise to the supplicant of an answer, in general—as indicated by the word "when"—not universally. Therefore, there is no need to restrict it by the "will" [of Allah]—as alluded to in His saying, the Exalted, in another verse: "And He removes that for which you supplicated, if He wills"—nor to argue that answering a supplication is different from fulfilling a need, because the answer is His saying, the Glorified and Exalted: "Here I am, My servant." This is a promise fulfilled for every believer who supplicates. Nor is there a need to restrict the supplication to that which contains no sin or severing of kinship, or the supplicant to the obedient and humble. True, being such is more conducive to an answer, especially at specific times, known places, and in the well-known manner. Yet, the answer might be delayed absolutely, or delayed in favor of a substitute. In the Sahih, from Abu Sa'id, the Messenger of Allah—may the blessings and peace of Allah be upon him—said: "There is no Muslim who calls upon Allah with a supplication that contains no sin or severing of kinship, but that Allah, the Blessed and Exalted, gives him one of three things: either He hastens the answer for him, or He stores it for him [in the Hereafter], or He turns away from him a like amount of evil." The verification of this will come, if Allah the Exalted wills.
"So let them respond to Me"—that is, let them seek My answer to them when they call upon Me, or let them answer Me when I call them to faith and obedience, just as I answer them when they call upon Me for their needs. "Responding" (istijaba) and "answering" (ijaba) are one and the same; it means to conclude one's request by granting the desired object, from jawb (the cut), meaning to sever [the state of waiting]. This is what the majority of exegetes hold. The phrase "and let them believe in Me" does not render this superfluous, because it is a command for steadfastness and persistence in faith.
"That they may be rightly guided"—that is, that they may be led to the interests of their religion and their worldly lives. The root of the word (rushd) is the attainment of good. It has been recited with the shin both fatha and kasra.
When He, the Glorified and Exalted, commanded them to fast the month and observe the prescribed period, and urged them to perform the duties of takbir (magnifying Allah) and gratitude, He followed it with this verse, which indicates that He, the Exalted, is fully aware of their actions, hearing their words, and rewarding them for their deeds, as a confirmation of it and an incitement toward it. Alternatively, when the rulings on fasting were abrogated, He mentioned this verse, which denotes the perfection of His knowledge of the condition of His servants, the perfection of His power over them, and the pinnacle of His kindness toward them, in the midst of the abrogation of rulings, to ground them in faith and confirm them in responsiveness. For the position of abrogation is a place for misgivings and instability. Thus, the sentence, according to both interpretations, is an interpolation between two connected discourses, the meaning of one being what preceded, and the second being His saying, the Glorified and Exalted: [Verse 187].