Tafsir of At-Tariq 86:7

Proceeding from between the backbone and the ribs. meaning, the backbone (or loins) of the man and the ribs of the woman, which is referring to her chest. Shabib bin Bishr reported from Ikrimah who narrated from Ibn Abbas that he said,

يخرج من بين الصلب والترآيب

(Proceeding from between the backbone and the ribs). "The backbone of the man and the ribs of the woman. It (the fluid) is yellow and fine in texture. The child will not be born except from both of them (i.e., their sexual fluids).'' Concerning Allah's statement,

إنه على رجعه لقادر