[avaiguite]

With all due respect but should the translation be like,
To fill someone in the heart is only the heart's destruction ..
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I though kaleja meant to destroy ?

Literally Kaleja means Liver so is jigar..
but as a metaphor often expressed when speaking about feats of courage.. like mian jigar ki baat hai..

so here my bro it means that to contain the Tajalli of Allah befits only the courage of the heart.. whereas we know that Mount Toor couldnt withstand and got burnt..

duas ..

wa assalam..