One day Hazrat Muhammad sallallahu alehi wasallam went to Hazrat Saad RA's home to meet him. He (pbuh) was used to of taking permission before entering into anyone's home so when he arrived at Hazrat Saad's place he said 'Assalam o alaikum' to inform him of his arrival. Hazrat Saad replied in low voice that Muhammad sallallahu alaehi wasallam couldn't hear. He said the salaam again and Hazrat Saad replied in that low voice this time too. Third time, Rehmaty Aalam (peace and blessings be upon him) said the salaam rather loudly still Hazrat Saad replied in low voice which he(pbuh) missed again. It was his(pbuh) another rule that if nobody replies on three calls he would return. So, he was about to turn away when Hazrat Saad RA came out hurriedly and said "Come inside. I heard each of your salaam and was replying to it in low voice. The reason was to gain maximum of your salaam." Hazrat Muhammad (pbuh) smiled at the passion of his devotees and went inside with him.
Compiled by: Hafiz Abdul Shakur Sheikhupuri