Prophet Mohammad said God is Kabir - Garib Das Ji
God Kabir met Prophet Mohammad and took him to his own lok (place). However Prophet Mohammad did not show a desire to reside there. Prophet Mohammad was then sent back to the earth.
Prophet Mohammad got the commandment to keep fasts, do azaan and Namaaz. However there was no order to do any slaughtering or sacrifice of animals. Obeying those commandments, Prophet Mohammad never slaughtered an animal.
Speech by Garib Das Ji Maharaj.
In this speech Garib Das ji has described interactions between God Kabir and Prophet Mohammad. It also describes how God Kabir brought a cow back to life to help Prophet Mohammad in front of his followers to keep his pride. At that point Prophet Mohammad addressed God Kabir as the Supreme God.
Sat Granth Sahib by Garib Das ji Maharaj - Ath Mohammad Rameni