قالَ رَبِّ اجعَل لي آيَةً ۚ قالَ آيَتُكَ أَلّا تُكَلِّمَ النّاسَ ثَلاثَ لَيالٍ سَوِيًّا

[Zechariah] said, "My Lord, make for me a sign." He said, "Your sign is that you will not speak to the people for three nights, [being] sound."