Reference: al-Imaam Ibn Baaz – duroos wa mawaaqif wa ‘ibar – Page 14
It has been narrated that he valued his time to such an extent that:
If he requested something from someone on the other end of the telephone, and was required to wait for a response, he would pass his time glorifying Allaah [saying: Subhaa-nAllaah] and seeking forgiveness from Allaah [saying: astaghfi-rullaah].
