Discussion of how apparent differences lead to internal differences, and the evidence for this from the hadith regarding straightening the rows

The Shaykh : And among this is the hadith that came in the Sahih that the Prophet (peace and blessings be upon him and his family) would not say the takbir for the prayer until he had ordered the straightening of the rows. He had several phrases when he ordered the people to straighten the rows. Among those related to our topic is his saying (peace and blessings be upon him): .
This is a physical straightening, as is known in the practical Sunnah, that the Prophet (peace and blessings be upon him) would, when straightening the rows, say to the one who was behind, "Move forward," and to the one whose body was protruding, "Move back and straighten." This straightening is something the Messenger (peace be upon him) ordered, and he linked the difference in that to the fact that it is a cause for the hearts of those who differ in straightening the row to differ. So he said (peace and blessings be upon him): . Thus, he (peace and blessings be upon him) made the difference among the Muslims standing in the row for the Lord of the Worlds—this difference—a cause for discord to occur between them themselves in their hearts. And this discord in the heart undoubtedly leads to the corruption of the Ummah and its weakness, and it may lead to its complete disappearance. In reality, this is something that scholars and students of knowledge should note: that the weakness, humiliation, and disgrace of the Muslims today, to the point that Allah (Mighty and Majestic) has subjected them to the most humiliated of nations, as the Qur'an testifies, is caused by their distance from the Shari'ah, sometimes in understanding, sometimes in practice, and sometimes in both understanding and practice. Many people never realize that a Muslim's rectification of his outward appearance is an obligatory duty that Islam has encouraged and ordered the Muslims to perform. They believe that these matters—or the best of these people are those who believe that these matters are formal, outward things that Islam does not give much weight to.