Sanatana Dharma - Aka Hinduism (1st Bin)

[Guest]

अग्ङं गलितं पलितं मुण्डं दशनविहीनं जातं तुण्डम्।
वृद्धो याति गृहीत्वा दण्डं तदपि न मुञ्चत्याशापिण्डम्।।
<b>अग्रे वहिः पृष्ठे भानुः</b> रात्रौ चुबुक समर्पित जानुः।
करतल भिक्षस्तरूतल वासः तदपि न मुञ्चत्याशा पाशः।।

Above is part of Sri Adi Shankar's Bhaj govindam. Below is the meaning in Hindi and English. I did not understand the real meaning of this part "पृष्ठे भानुः"

वृद्धावस्था में शरीर जर्जर हो गया है, सिर के बाल सफेद हो गये हैं, दाँत गिर गये हैं, छड़ी के सहारे चलना पड़ता है अर्थात् मृत्यु निकट आ गई है किन्तु आशाओं का बन्धन अब भी नहीं टूटा।
<b>आगे अग्नि, पीछे सूर्य</b> और रात्रि में घुटनों में ठोढ़ी लगाये रहने वाले तथा हाथ पसार कर भीख मांगने वाले और पेड़ के नीचे सोने वाले भी आशा के बन्धनों से मुक्त नहीं हैं।

Old age has decayed the body; hair have grayed; teeth have left; with cane one gets to walk; death knocks at the doors; and yet bondage of hopes have not left you? <b>Fire is ahead, and sun behind</b> ; those who sleep with chin done to knees; and those who beg spreading their palms; as well as those who sleep in open below the trees; are even those free from the bondage of hopes!!

I did not understand the part "fire ahead; and sun behind - अग्रे वहिः पृष्ठे भानुः". For fire ahead, I imagine it indicates - pyre of death awaits ahead? But what does the sun behind mean in that context?

Someone knows the real meaning?