Applying kumkum or sandalwood paste on the forehead after every puja is considered necessary. But, some pandits apply it on men’s forehead and on women’s bangles.According to our scriptures, Brahmins should apply tilak on married women’s bangles and not on her forehead. The reason behind this is because no man other than the woman’s husband should touch her.
In Hindu scriptures, it is believed that the touch of another man can ruin that woman’s pativrat (devotion for her husband). A married woman cannot be touched by any other man. Only in case she is not well, a doctor can touch her.
It is also believed that applying tilak on the bangles (which is also a sign of married women) increases the life of her husband. Hence, applying kumkum on the bangle helps her preserve her pativrat along with keeping the tradition of applying tilak after puja.
