It is also stated in the Holy Qur'an...
Do not go to the graveside of the hypocrites as you are doing with respect to the graves of the faithful, and do not pray for their souls nor pray over their graves because they defied Allah and His Apostle and they are transgressors. That ziyarah is an indisputable principle and the presence of believers at the graveside of one another is unquestionable although there may possibly be differences of opinion among some Muslim schools of thought concerning the secondary features of ziyarah .
It is also recorded that Abu Bakr, 'Umar and 'Uthman, like the Prophet (s), also used to perform ziyarah . The daughter of the Prophet of Islam (s), Hadrat Fatimah az-Zahra ( 'a ) would also visit the martyrs of Uhud two days a week. During his visit to the martyrs, especially in the ziyarah to Hamzah and Mus'ab ibn 'Umayr, the Holy Prophet (s) would recite this verse, رِجَالٌ صَدَقُوا مَا عَاهَدُوا اللَّهَ عَلَيْهِ. Men who fulfill what they have pledged to Allah .
[^6] In addition to this, it is thus recorded in the book, As-Sahih that Abu Sa'id al-Khudri would extend salutations to the grave of Hamzah… Umm Salamah, one of the honorable wives of the Prophet (s), and individuals such as Abu Hurayrah, Fatimah Khuza'iyyah, and 'Abd Allah ibn 'Umar al-Khattab also used to perform ziyarah to this group of martyrs.[^7] It is thus recorded in the valuable book, al-Ghadir under the section, “Virtues and Merits of Abu Hanifah” { Bab Fada'il wa Manaqib Abu Hanifah }: Whenever he would go to Baghdad, Imam ash-Shafi'i would pay a visit to the grave of Abu Hanifah.