I say:

The great ḥadith scholar Abū al-Qāsim Ibn ʿAsākir, in his biography of Abū Muslim ʿAbd Allāh ibn Thawb al-Khawlānī, cites this story in fuller detail. Through the chain of Baqiyyah ibn al-Walīd—who said, “Muḥammad ibn Ziyād narrated to me”—he relates that whenever Abū Muslim campaigned in Byzantine lands and the army reached a river, he would announce, “Cross, in the name of Allah.” He would ride ahead of them, and they would pass over the water; the animals’ legs were scarcely wet above the knees, or only a little higher. When everyone had crossed, he would ask, “Has anyone lost anything? If so, I guarantee its return.” One man purposely threw his feedbag into the river. After they reached the opposite bank the man said, “My feedbag has fallen into the river.” Abū Muslim told him, “Follow me,” and they found the bag caught on some branches. “Take it,” he said. (1)

Abū Dāwūd also transmitted the report, through Ibn al-Aʿrābī from him, from ʿAmr ibn ʿUthmān, from Baqiyyah, with the same wording. Abū Dāwūd then added:

“Mūsā ibn Ismāʿīl told us—Sulaimān ibn al-Mughīrah told us—from Ḥumayd: Abū Muslim al-Khawlānī once came to the Tigris when it was in full flood, sweeping along logs. He halted, praised Allah, recalled how the Children of Israel crossed the sea, then prodded his mount and it entered the water. The people followed until they were all safely across. He then said, ‘Has anyone lost any of his belongings, that I may pray to Allah to restore them to me?’” (2)

Ibn ʿAsākir gives another chain: from ʿAbd al-Karīm ibn Rashīd, from Ḥumayd ibn Hilāl al-ʿAdawī, who said:

“My cousin, my father’s brother, told me: I marched with Abū Muslim in an expedition. We reached a raging, unfamiliar river and asked the villagers, ‘Where is the ford?’ They answered, ‘There has never been a ford here; the nearest ford is two days’ journey downstream.’ Abū Muslim prayed, ‘O Allah, You enabled the Children of Israel to cross the sea. We are Your slaves, striving in Your cause—so let us cross this river today.’ Then he said, ‘Cross, in the name of Allah.’ My cousin continued, ‘I was mounted and resolved to ride directly behind him as the first of the people.’ By Allah, the water did not even reach the horses’ bellies until everyone had crossed. Abū Muslim then halted and proclaimed, ‘O Muslims! Has anyone lost anything, that I may ask Allah, Exalted is He, to return it?’” (3)

These tokens of divine favor granted to such saints are, as has been explained, miracles of the Messenger of Allah—may Allah bless him and grant him peace—for they were attained only through the blessing of following him and the good fortune of his mission. They serve as evidence for the faith and fulfill urgent needs of the Muslims. They resemble the miracle of Noah, peace be upon him, who moved upon the water in the ark Allah commanded him to build, and the miracle of Moses, peace be upon him, when the sea was parted. In certain respects they are even more astonishing: the companions travelled on the very surface of the water without any support beneath them, and upon flowing water at that—walking on a swift current is even more wondrous than crossing calm, still water, immense as the floodwaters undoubtedly were.