There is a question regarding interlocking ones fingers. According to the halacha it is permitted but Kabbala says not to do it.
The Aruch HaShulchan brings L'Halacha (OC 91:7) that in times of Za'am or raging tzorus, one should daven with his hands clasped together and his fingers interlocking. However says the Aruch HaShulchan in times of peace you should not do so because it causes Din Shamayim to be brought down on you.
The Piskei Tshuvos (95:5) brings that Arizal was makpid that you should never hold your hands in that manner and it is bad Mazal. Rav Chaim Palagi writes that one should stop his wife or children from doing this, ever, and especially in times of sickness or the Aseres Yimei Tshuva.
The following video shows that Rav Eliashiv does in fact interlock his fingers.