Whenever asked about a matter, Zayd b. Thâbit – Allah be pleased with him – would himself ask, “Has this happened?” If they told him that the matter had not yet occurred he would not inform them of an answer, but if they told him it had happened he would answer them.

Al-Âjurrî, Akhlâq Al-‘Ulamâ` no.81; Al-Khatîb, Al-Faqîh wa Al-Mutafaqqih Vol2. P13.