One should avoid friendship or warm relationship with wicked person. (like a coal). if hot (he) burns (your hands) if cold, (he) blackens (your) hands. (i.e. if he is bad to you, they will surely cause some problem to you, but even if he is good to you, contact alone will cause some problem).
Here the poet describes the supremacy of Subhashitas. On this earth the ''RASA''(implied meaning) of subhashitas is so sweet that the grapes felt ashamed (of its sweetness) and crestfallen. The sweeter sugar got hard (Ashma - stone ) and the sweetest ''AMRITA'' ( necter) pulled itself back to the heaven.
It is improper to start digging the well after the house has caught fire! We should be pro-active i.e. we should have the solutions ready even before some problem comes to us.