We are here to realize our own divinity so that we can merge back with the Pure Light that we came from. In order to do this, it's important to realize the nature of the Divine. One of the qualities of the Divine, that the Guru talks about, is sweetness.
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Mith Bolrha Ji Har Sajan Suami Mora
Hou Samal Thaki Ji Ohu Kade Na Bolai Koura
My Dear Lord and Master, my Friend, speaks so sweetly. I have grown weary of testing Him, but still, He never speaks harshly to me.
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This sweetness doesn't mean sugar coating. This is not forced or fake in any way. It's a genuine kindness, compassion, respect, and consideration.
If someone is dear to us we use pet names like sweetie, and honey. That which is bitter, we spit it out. Harsh and unkind words are not appreciated by either party. Not just the person receiving it, but it's damaging to the person saying it as well. These words are toxic to our mind and body.
We do need to express anger. So, what we need to do, in order to not say harsh words, is to become calm before expressing these feelings. Let a few hours pass or even a whole day. Your expression of that anger will be very different. You may be able to muster some more empathy, kindness, and understanding of the other person.
Negative and angry communication affects us even more than the person it's directed at.
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Naanak Fikai Boliyai Tan Man Fikai Hoe
O Nanak, speaking insipid words, the body and mind become insipid.
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Related Article: Sweet Speech - The "Magic Mantra" for all Gursikhs