विधिहीनमसृष्टान्नं मन्त्रहीनमदक्षिणम्।श्रद्धाविरहितं यज्ञं तामसं परिचक्षते॥
vidhi-hīnam asṛṣṭānnaṃ mantra-hīnam adakṣiṇamśraddhā-virahitaṃ yajñaṃ tāmasaṃ paricakṣate
Word by word
The verse says
An offering made with no rule followed, no food shared out, nothing said over it and nothing given to anyone, and no faith behind it - that one is called dark.
In plain words
Five absences. Count them.
No form, no food shared, nothing said, nothing given, and nothing meant.
The last is the one that matters. Śraddhā-virahita - emptied of faith. The other four could be forgiven. A thing done with nothing behind it at all is not really an act. It is a motion.
Where you've felt this · in relationships
You send the message on the birthday. It is the same message you sent last year, which was the same as the year before. You do not think about the person while you send it and you do not think about them afterwards. They probably know. The message arrived, and nothing came with it.
Going deeper
Something done with nothing behind it is the state being described, and it is more common than either of the others.
Five things are missing and the last one carries the rest. Śraddhā-virahita means emptied of trust, of weight, of meaning - gone through rather than done. The form can be perfect and this can still be true. A ritual performed exactly right with nobody at home inside it falls in this verse.
That is an uncomfortable place to look, because the other two states at least have something in them. Clarity has care. Drive has hunger. This has neither, and it rarely announces itself, because on paper nothing is being neglected.
The test is whether you would notice if you stopped. Most of what belongs here would not be missed by anybody, including the person doing it, which is exactly what makes it so easy to keep up for years.