जानकीरक्षणार्थं वा is it to protect Janaki, श्रमाद्वा or is it because he was tired, नोपलभ्यते we are not able to understand, अथवा or else, तस्य his, श्रमः tiresomeness, कः what, तेन by him, सैव she alone, अभिरक्षिता is spared.

"It is not clear whether he spared that place for protecting Janakai or he stopped due to exhaustion. What is fatigue for him? It must be to save her that she is spared by him.