"And they swore by Allah their strongest oaths"—meaning to the utmost extent of their oaths—"that if a sign came to them, they would believe in it." Allah said to His Prophet: "Say, 'The signs are only with Allah.' And what makes you perceive," meaning: what makes you know, "that if they came, they would not believe?"
Muhammad said: It is read "innaha" (that it) with the kasra on the alif, as an initial clause; and it is read "annaha" (that it) with the fatha, meaning: perhaps they [will not believe]. Abu Ubayd mentioned this.