For connected madd (muttaṣil) and separate madd (munfaṣil), the source reports two, two-and-a-half and four alifs in different recognized measures. It additionally reports qaṣr for munfaṣil.
These are transmitted reading options, not arbitrary numbers to change at will in each āyah. Their combinations are subject to rules.
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Connected and separate madd: reported lengths
Madd Lengths and Permissible Combinations — Ṭūl, Tawassuṭ, Qaṣr and Consistency
For connected madd (muttaṣil) and separate madd (munfaṣil), the source reports two, two-and-a-half and four alifs in different recognized measures. It additionally reports qaṣr for munfaṣil.
These are transmitted reading options, not arbitrary numbers to change at will in each āyah. Their combinations are subject to rules.