The hadith of Abu Bakrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Shall I inform you of the greatest of the major sins?" This is the tool of presentation with which the Prophet

The Shaykh : The hadith of Abu Bakrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said This is the tool of presentation with which the Prophet (peace and blessings be upon him and his family) opened his speech to alert the listener to a matter of great importance. Therefore, he said This is the greatest injustice, the greatest of the major sins, and the most severe of sins in punishment, because whoever associates partners with Allah, Allah has forbidden him Paradise, and his abode is the Fire, and there are no helpers for the wrongdoers.
The second is undutifulness to parents, meaning severing their rights. The parents are the father and the mother. It is obligatory for a person to be dutiful to them, to serve them to the best of his ability, and to obey them except in what entails harm to him or disobedience to Allah (Mighty and Majestic), for in that case, he is not required to do so.
in order to magnify what he was about to say. The Prophet (peace and blessings be upon him) magnified the matter of this because of its frequent occurrence and the people's lack of concern for it, so he showed the people that its matter is great. He was speaking about associating partners with Allah and undutifulness to parents while leaning, then he sat up out of concern for the matter. This is evidence of the greatness of bearing false witness and speaking falsehood. So a person should repent to Allah (Mighty and Majestic) from this, because it entails, as I said, wronging himself and wronging the one for whom he testified. And success is from Allah.