‏الصلاة : Hadeeth No:737 Anas b. Malik reported: They (the Companions) discussed that they should know the timings of prayer by means of something recognized by all. Some of them said that fire should be lighted or a bell should be rung. But Bilal was ordered to repeat the phrases twice in Adhan, and once in Iqama....

‏الحج : Hadeeth No:2788 'A'isha (Allaah be pleased with her) reported that she entered in the monthly period at Sarif, and took bath at 'Arafa (after the period was over). The messenger of Allaah (sallAllaahu alayhi wa sallam) said to her: Your circumambulation between al Safa and al-Marwa is enough for your Hajj and 'Umra...