Ahmad Hasan argues that since the Quran is valid for eternity, the solution to any contradictions found within it is not to abrogate earlier verses, but to recognize that Qur'anic revelations varied to keep "pace with the changing conditions and environment" and must be studied and applied to their "historical context". In the case of the Meccan surahs that ask "Muslims to be patient and to tolerate the aggression of the infidels" (for example: Q.2:109; Q.6:106; Q10:109; Q15:85; Q29:46), and which conflict with the Medinan Sword Verse (Q.9:5) that calls on Muslims to attack "the infidels and kill them wherever they are found"; neither is a pure/basic doctrine, nor a temporary tactic. The Meccan surahs were revealed when the Muslims were/are weak and could not retaliate against aggression, Medinan surahs when Muslim were/are strong. The proper command to implement is the one for "conditions similar to those in which they were revealed" — apply the Sword Verse when Muslims are strong, the earlier verses when they are not. Mohammed al-Ghazali also states, "There is no contradiction in the Qur'an whatsoever, for every verse has a context within which it functions. ... He, the Legislator who knows the conditions in which the verses may be applied, and it is in this manner that the Qur'anic verses are to be considered in light of the state of human affairs — with wisdom and exhortation."