The manthram भद्रं कर्णेभिः actually means

The five Shanti Mantras.. also invoke blessing and seek welfare from the celestial beings..

The manthram भद्रं कर्णेभिः actually means... let us listen by means of ears nice and praiseworthy things by the grace of Gods, let see good things, and with firm limbs and endowed with healthy and happy bodies, let us spend our span of life as ordained by the Divine will.

 And there are very many instances in our scriptures where it is stated unequally that we are what our activities make us.. and even the vice versa..

This idea is a sequel to the theory of Karma.. The inevitability of cause and effect.. We can compare the scenario to any static or dynamic state as described in theoretical physics..

Newton's third law.. For every action there is an equal and opposite reaction..

If an elastic string is clamped between two nails firmly fixed to tow immovable points and the string is pulled at the centre, then the string starts vibrating and by way of reaction it will be in a state of oscillation for some time till it is brought rest through the attenuation effected by air-friction perhaps..

This is how a veena or violin works..

So it is evident that the vibration continues for some time after the force is applied and an otherwise quiet thing is pulled and pushed for sometime afterwards even as a result of the first act.. or even after the application of force has ceased..

Likewise,the good or bad Karma performed by a person sets up such oscillation by way of being subjected to the consequences of the karma.. and the action and reaction need not be simultaneous..

While observing the usual happenings around us the time-lag between action and reaction would be measurable with our senses..

Therefore we are able to correlate the cause and its effect is those cases.

But our belief is that the theory of Karma extends to many lives and we lose count of and we are not able to remember what we did at a point of time years away, lives away..

Therefore we are not able to find and/ or conceive the logic of the theory of Karma..

But for the Supreme controller, He sees the past, present and even the future.. So he can enforce the law with equity..

We can take the example of a small puddle of water collected after a rain..

An ant drawn into this puddle would feel listless as if it has entered an ocean..

But for a man viewing this, the bafflement of the ant would look funny..

Therefore it would be a fallacy to state that a person who is doing good things is faced with difficult situations in life..

We have to take a long-term perspective.

The flow of life is also like the flow of seasons..

The spring comes and the winter follows..

One who has lived only in spring will see the whole world as a bouquet of flowers.. One who has lived in winter would perhaps see the world as fully soaked..

Both experiences are real in their time frames but the real world is neither flowers alone, nor soggy for ever..

The span of our vision and other cognitive faculties are quite limited.