tension:confusion

sweet-buds

1. The problem statement, all variables and given/known data lets say we have 2 blocks as shown.
[]->T1----T1-<--[]

both blocks are joined by a common rope having a tension T.lets say when the blocks are pulled apart, the tension acts in the direction on the blocks as shown in figure as they try to prevent the sting from expanding. but lets say if the blocks are ppushed towards each other, the ropes would begin to slack and tension would become zero. Inthis case ,does the tension acton the blocks in the opposite direction as shown in the diagram as to oppose the slacking of rope or they simply continue to act int the same direction?if that were the case tension would begin to push the two blocks.
I am asking this bcoz I am confused with 2 properties of tension:
Tension cannot bear compression.
Tension can never push a rope or body




2. Relevant equations



3. The attempt at a solution

Gear300

Tension can be noted as...well...for example: the force that pulls a block when it is attached to a string. If the string slacks, then tension is 0. Another example: you take 2 blocks and have a string attached between them; if you straighten the string by pulling the blocks in opposite directions and then let go, the string will slack due to tension. At some point, it does not slack further because the tension is 0 (there is no more pull). Tension tends to pull on the object its attached to, not push.