With joy and trepidation, I would like to cite from the Haggada of Rav Kanievky “a short issue” we all are very aware of but the Rav describes [without any “buts”] the degree of its extreme importance and for sure he himself meticulously followed this himself his whole life..זצוק״ל
Quote: ….that if someone is scrupulously honest, the blessings that he will give will be fulfilled.
Anyone who speaks the truth and does not speak falsely-not even in his mind-all his words will be fulfilled: he can decree something and Hashen will fulfil it, as is stated
You would utter a decree and I would be done כח וְתִגְזַר-אֹמֶר, וְיָקָם לָךְ; Iyov 22:28

May G-d give us the strength and the blessing to try to emulate this Mida everyone to the best of his possibilities with full emuna.