Kabbalah 1 Tawarikh 7:1: Sha'arei Orah

It therefore is necessary for a person to prepare himself for prayer and properly direct his thoughts, in a manner that his prayer will not be obstructed and his request will not return emptyhanded. About this our sages, of blessed memory stated,¹⁶Talmud Bavli, Berachot 30b “A person should always take stock of himself. If he is able to focus his heart, he should pray, but if not, he should not pray,” meaning, if in his prayer he is able to focus on HaShem’s-יהו"ה title that pertains to his prayer, he should pray, but if not, he should not pray.