Is the recitation of "Hasbiyallahu la ilaha illa Huwa, 'alayhi tawakkaltu wa Huwa Rabbul 'Arshil-'Azeem" seven times established in a sound Hadith, and is the recitation of "Hasbiyallahu wa ni'mal Wakeel" seven times established in a sound Hadith?

Whoever says "Sufficient for me is Allah; there is no deity except Him. Upon Him I have relied, and He is the Lord of the Great Throne" seven times in the morning and in the evening, Allah will suffice him for whatever worries him, and Al-Arna'ut authenticated its chain of narration. As for "Sufficient for us is Allah, and [He is] the best Disposer of affairs," there is no evidence that it should be said seven times, though Abraham, peace be upon him, said it when he was thrown into the fire.