(1) This report is transmitted by Ibn Khuzaymah in his at-Tawhid, p. 105; al-Bayhaqi in Al-Asma’ wa’s-Sifat, p. 501; Ibn Abi Zamanin in Usool al-Sunnah, hadith no. 39 (vol. 1, p. 309); al-Dhahabi in al-Uluww, p. 64; al-Darami in Ar-Radd ‘ala’l-Jahmiyyah, p. 21, and in Ar-Radd ‘ala Bishr al-Marisi, p. 73; and al-Lalika’i in as-Sunnah, hadith no. 659 (vol. 2, p. 395). Al-Bayhaqi also records from Abu Hurayrah a marfu‘ (elevated) version in the same sense (p. 505). The wording attributed to Ibn Mas‘ud is weak in this chain due to Ḥasan ibn Ja‘far (declared weak by al-Ḥāfiẓ; see at-Taqrīb, 1/164) and ‘Āsim ibn Bahdalah (see the earlier discussion). What the compiler here cites is part of Ibn Mas‘ud’s statement: “Between each heaven and the next is a journey of five hundred years, and between the heaven and the earth a journey of five hundred years….” A similar version is found in Ibn Khuzaymah and others, who continue the report essentially as here. Earlier, in the hadith of al-‘Abbās ibn ‘Abdul-Muṭṭalib (no. 15), the distance between each heaven was given as seventy-two or seventy-three years. The version from Ibn Mas‘ud is more widespread, as al-Ḥāfiẓ al-Bayhaqi notes in Al-Asma’ wa’s-Sifat. Any apparent contradiction is resolved by Ibn Khuzaymah’s remark: “Some may think that al-‘Abbās’s report on the distance between the heavens contradicts Ibn Mas‘ud’s report, but knowledge shows that travel varies by the speed of mounts—horses, camels, mules, donkeys—and even among human travelers. Thus, the Prophet (peace be upon him) may have referred to the pace of swift riding horses when he said ‘seventy-two or seventy-three years,’ while Ibn Mas‘ud referred to the ordinary pace of men or of slower pack animals. Therefore, neither report truly contradicts the other. This is our methodological principle: any two reports may be reconciled in meaning rather than declared mutually exclusive” (at-Tawhid, p. 108). Al-Bayhaqi concurs: “It may vary according to the strength or weakness, lightness or heaviness of the traveler: the strong journey faster and the weak slower” (Al-Asma’ wa’s-Sifat, p. 506). I would add that, assuming both reports are sound, their reconciliation is as above—and is further illustrated by modern means of transport (cars, airplanes, spacecraft) of differing speeds. Reconciling such narrations is therefore not difficult in light of the imams’ statements.