Originated from contemporary spoken Hebrew, it defines a situation where an agitated person, most probably with a splitting head-ache, hang-over or before his first morning cofee, is asking another to calm down, don't use verbose sentences, speak slower or not to overload his aching head with issues that requires listening, thinking or focusing.
This phrase, originating from a leading Israeli comedy show, is well curved in contemporary spoken language and it means (in a free translation): - "slow down your shutter, your "homing in" on me in an overloading manner".
Gesture-aware people most often accompany this phrase with an overdramatic facial expression of a person abrupting his 1-hour sleep after having an awful hang-over, by some woody-allen style geek who lightens up the room and asking him if he read about the new star names EL-12141 reently discovered in our solar system.
You have just broken up with your girlfriend, and you have a splitting headache after a long night of non-fruitful pick-up bar road-show, and you have just been awaken your MBA roomate who opens your room windows wide, turns on the music loudly, and tells you in a patronizing voice "look at you, I am going to take care of you. Do you want me to prepare you an organic Soya drink? and then, we can practice some Yoga, and then..."
You then bluntly, with a suffering voice, eyes half-shut,your right hand blocking the rude sunlight coming from the windows, looking at him and, right before falling asleep again, saying "Tsamtsem, ata lo ba-li-tov".