In the original Sanskrit, this is daiveea vakya.
This is a peculiar faculty that sometimes develops in those who are extremely advanced upon the spiritual path. As the Brihadaranyaka Upanishad says,“ That speech is divine, by which whatever one speaks comes to be.” This ability comes as a result of living a life of absolute purity and integrity. There is no element of soothsaying or prediction in this, it is something else altogether. These people say things, and they happen to come true. Ramakrishna Parmahamsa was famous for this trait. Such a stickler was he for the true word that if he told somebody to meet him on Tuesday, he would not accept a suggestion that they come on Wednesday. He had said Tuesday and now he could not go back upon it. The disciples and followers of Sai Baba of Shirdi too used to observe that they had better listen carefully when the saint was speaking. If he made a suggestion, to go against it would inevitably teach them a sharp lesson. The munis, a class of silent sage in India, keep a vow of silence precisely because their words have become so potent now. Anything they say will come true and it is best to hold their peace.
It also explains the extraordinary emphasis on true speech that the Indian tradition demands.
There is a peculiar shadow side to this phenomenon. Some people have an unfortunate talent of accurately predicting disasters and unpleasantness. Their words come true for negative things only. They are the people reputed to have the black tongue and disliked actively by all who know them. This is a perverse reflection of divine speech, actually. Such people are full of anger, hate, jealousy and other negative emotions. They almost all have one unvarying characteristic, the nasty personality trait the Germans call Schadenfreud - taking a malicious delight in the misfortunes of others. And of course purity and integrity are the last things on their minds, though they may make a big noise about it. Naturally they have a fine instinct for nasty happenings, but it is a talent that does them no good and actually harms their spirit.