For ʿalā ḥaddih, both conditions apply: the first sākin is a madd letter and both sākin letters occur within one word. The book permits this form.
ʿAlā ghayr ḥaddih applies when the first is not a madd letter or the two are not in one word. In connected recitation this is normally resolved by omission of the first madd sound or by giving an appropriate vowel.
Opening interactive controls...
How the two categories are distinguished
Meeting of Two Sākin Letters — ʿAlā Ḥaddih, Ghayr Ḥaddih and Tanwīn
For ʿalā ḥaddih, both conditions apply: the first sākin is a madd letter and both sākin letters occur within one word. The book permits this form.
ʿAlā ghayr ḥaddih applies when the first is not a madd letter or the two are not in one word. In connected recitation this is normally resolved by omission of the first madd sound or by giving an appropriate vowel.