If someone swears and says 'in sha' Allah' and then does not do it, does he owe expiation?

Original answer — Shaykh ‘Abd al-‘Aziz ibn Baz

Question

«إذا حلف إنسان، أو نذر، ثم أعقب قوله ذلك بكلمة: إن شاء الله، ولم يفعل ما نذر، أو حلف من أجله، فهل عليه كفارة؟»

English translation (unreviewed): If a person swears an oath or makes a vow, then follows his words with 'in sha' Allah' and does not do what he vowed or swore for, does he owe expiation?

From the text of the answer

«الصواب لا كفارة عليه، إذا قال: والله لأفعلن كذا -إن شاء الله- أو نذر لله علي لأفعلن كذا -إن شاء الله- فلا شيء عليه؛ لأن هذه المشيئة تجعل له فرجًا ومخرجًا، وفي الحديث الصحيح يقول ﷺ: من قال في يمينه: إن شاء الله؛ فلا حنث عليه نعم.»

English translation (unreviewed): The correct view is that he owes no expiation. If he says 'By Allah I will do such-and-such, in sha' Allah' or 'I vow to Allah that I will do such-and-such, in sha' Allah', there is nothing on him, because this qualification gives him a way out; and in the authentic hadith he ﷺ says: “Whoever says in his oath ‘in sha' Allah’ has not broken it.” Yes.