yum yum vaapi smaranbhaavam tyajatyante kalevaram
tam tamevaiti kaunteya sadaa tadbhaavbhaavitah (Gita 8/6)
O Kaunteya (Arjuna), whatever object or being a man thinks of at the time of his death or departure from the body, that alone does he attain, being ever absorbed in its thought. (in other words he takes birth in those wombs) (Gita 8/6)
A being is reborn in the body he thinks of at the time of death. As is his nature, he thinks accordingly at the time of death. As a man tending to a pet dog thinks of it at the time of death, he is born as a dog. As the programme broadcast from a particular radio station is received at a particular wave-length and then spreads in the form of sound, the thought of a dog with which he has been connected is caught by him somehow. The soul with subtle and causal bodies enters the body of the dog via water, air (breath) or food etc. Thereafter, it enters the body of a female dog and takes birth as a puppy at the appropriate time. This can be explained with the help of an illustration. A person goes to a photographer and requests him to take his photograph. The photographer advises him to keep a smiling face without any movement. But when the photographer asks him to be ready, a fly sits on his nose and so he moves his facial muscles to get rid of that fly. The result is that in the photograph he appears with a distorted face. In the same way, a man is reborn according to his thoughts at the time of death.
As far as the time to take a photograph is concerned, we know it before hand, but we do not know the time of death. So, by purifying our nature and thoughts, we should be ever alert and think of Him at all times (Gita 8/5, 7).
In this directive of the Lord is seen His justice, as well as mercy. Generally, justice and mercy (compassion) seem incompatible, because if there is justice, there cannot be compassion (mercy), while having mercy, justice cannot be done. The reason is that in doing proper justice there is no leeway, but in mercy, concessions are made. As such, this rule is applicable to ordinary unkind human beings, not to the Lord, as He is the most gracious One, and is a disinterested friend of all beings, (Gita 5/29). So, all His ordinances and rules are full of justice and mercy.
Whatever being a man thinks of at the time of death, he acquires the same form on rebirth. If he dies thinking of a dog, he is reborn as a dog. This is God's justice. But He has given freedom of choice to man, to think either of a dog or of a man, or of God, and this is His mercy. A man can attain God, simply by thinking of Him, as he can obtain the body of a dog, by thinking of it. If a man starts thinking of God's justice and compassion, he will be attracted towards God alone.
